What is Rreverse Circulation Drilling
Time:2021-03-04 16:10:42From:This Site

Reverse circulation drilling, or RC drilling, is a form of percussion drilling that uses compressed air to flush material cuttings out of the drill hole in a safe and efficient manner.


RC drilling uses a drill bit that features round, protruding tungsten-carbide buttons, to cut through hard rock and earth. The drill rods themselves are hollow and feature an inner tube with an outer barrel (similar to air core drilling).


A pneumatic reciprocating piston (also known as a down hole hammer) delivers rapid impacts to the drill stem, transferring this energy through the drill bit. This extra concussive force hammers the bit into the rock, pulverizing it, while a rotational device ensures that the drill bit hits new sections of rock with each impact.

Inside the drill bit, a dual-walled drill pipe is used to achieve circulation, with compressed air getting injected between the tubes to flush the cuttings from the hole and up through the inner tube. The cuttings travel back up the tube to the surface, into a cyclone, where they go over a splitter that delivers the samples into a sample bag.

The exploration team then collects the samples, align them to the hole depth, and layout for their client to log. From here the sample is transported to their lab for assay.


RC drilling is commonly employed in open-cut mines and used for pit grade control and in delivering useful insight for mine planning and blasting. It has an optimal depth of between 300-500 metres.


RC grade control is extremely effective in defining boundaries between ore bodies and waste rock


RC drilling is ideal for exploration, as it delivers contaminant-free samples, which are collected at the drill itself and can be sent immediately for assessment. It also reduces handling time, which in turn can serve to reduce overall program costs.